JPS63120932A - Power unit mounting device - Google Patents

Abstract

PURPOSE:To reduce engine shake, by bringing only first movable board into closed condition under intermediate amplitude vibration such as shaking and resonating fluid in an orifice. CONSTITUTION:Movable clearance delta1 of a first movable board 13 is set to be large while a movable clearance delta2 of a second movable board 14 is set to be small under engine shaking. Consequently, the first movable board 13 moves without restriction of both stopper members 11, 12, but the second movable board 14 is restricted by a ring groove 12a in the second stopper member 12 and stopped so as to choke a liquid chamber 9 in the way. Consequently, the liquid in the liquid chamber 9 communicates through orifices 15, 15,... of the second stopper member 12 with a portion at the elastic film 8 side, so as to reduce the engine shake by the vibration suppressing effect produced through resonance of liquid passing through the orifices 15, 15,....

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a mounting device for mounting a power unit such as an engine on a base such as a vehicle body and suppressing noise from the power unit from being transmitted to the base. This is related to the improvement of.

(Prior art) Conventionally, as a mounting device for this scale, as shown in Utility Model Application Laid-open No. 59-164845@publication, etc., mounting devices have been used on both sides of the rotating shaft (roll shaft) of a so-called flank type engine (power unit). A mount is arranged and has a fluid chamber filled with an incompressible fluid inside, and elastically supports the engine on the vehicle body (base), and the fluid chambers of each mount are communicated with each other to allow movement of fluid. , and a communication pipe for correlating the pressure changes in both fluid chambers, and by utilizing the damping effect due to the resonance phenomenon of a predetermined frequency of the fluid in this communication pipe, for example, about 5Hz of the engine accompanying ON-OFF switching of the accelerator. It is well known that the roll motion of the roller is suppressed.

In addition, as another type of mounting device, for example, as disclosed in Japanese Utility Model Application Publication No. 59-108841,
Part of the wall of the fluid chamber in the same mount as above is made of an elastic membrane that deforms according to changes in fluid chamber pressure, and an orifice is provided in the fluid chamber, and the resonance of the fluid in this orifice causes the engine to Techniques are also widely known to reduce so-called engine shake, which is caused by vibrations from the road surface and unbalance of the wheels, and images are taken in a downward direction on the road at about 10 to 15 Hz.

Roughly speaking, there is a movable plate in the fluid chamber that is in the same state and vibrates together with the fluid when the amplitude of vibration is smaller than a predetermined clearance, but becomes an open state and closes the fluid chamber when the amplitude becomes larger than a predetermined clearance. It is also known that this movable plate is used to prevent the pressure in the fluid chamber from increasing and the vibration transmission rate to the vehicle body to increase in the event of a small turbulence.

(Problems to be Solved by the Invention) However, in these conventional methods, a specific general frequency range to be suppressed is determined for each of them, and it is difficult to reduce imaging other than that. For this reason,
For example, an engine's (582) turbulence is its roll vibration.
In order to achieve uniform reduction over a wide range of frequencies from the low frequency range of about 80 to 100 Hz or more, many types of mounts are required.

The present invention has been made in view of the above, and its purpose is to organically combine the above-mentioned three types of conventional technologies, thereby reducing the vibration of a power unit such as an engine through their synergistic effects. Equally reduce the frequency range from the low frequency range caused by roll vibration to the muffled sound range.

The purpose is to do so.

(Means for solving the problem) In order to achieve this object, the solving means of the present invention is arranged on both sides of a power unit such as an engine across the roll shaft, and an incompressible fluid is sealed inside. a mount for elastically supporting the power unit on a base such as a vehicle body; A communication pipe is provided to communicate the fluid chambers with each other to allow movement of fluid and to correlate pressure changes in both fluid chambers.

Further, each of the mounts includes a movable first movable plate disposed so as to partition the fluid chamber closer to the elastic membrane than the communication portion with the communication tube, and a movable first movable plate arranged to partition the fluid chamber closer to the elastic membrane than the communication portion with the communication pipe; A movable second movable plate arranged so as to partition on the membrane side and an orifice arranged so as to bypass the second movable plate are provided.

The movable clearance of the first movable plate is set to be larger than the movable clearance of the second movable plate.

(Function) With this configuration, in the present invention, when the power unit rolls vibrates around its roll axis at a low frequency of about 5 Hz, the amplitude of the vibration is large, so only the second movable plate in the fluid chamber of each mount Instead, the first movable plate also becomes closed,
Therefore, the fluids in each fluid chamber mutually move through the communication pipes, and the roll vibration of the power unit is reduced due to the damping effect due to the synergistic phenomenon of the fluids at this time.

In addition, this power unit can be
When a commotion occurs at about 15H2, both mounts are subjected to additional force in the same direction, so fluid is not exchanged through the communication tube.

Further, since the amplitude of the vibration is medium, the second movable plate is kept in the closed state, but the first movable plate, which has a larger movable clearance, remains in the same state. Therefore, as the power unit vibrates, the fluid in the fluid chamber moves through the orifice that bypasses the second movable plate in the closed state, and the resonance of the fluid in this orifice effectively reduces the imaging of the power unit. .

Roughly speaking, the power unit's imaging frequency is 80 to 100H.
When the sound rises to a muffled sound range of z or more, the amplitude of the imaging becomes small, and not only the first movable plate but also the second movable plate are in an open state. For this reason, the excitation force of the power unit is transmitted to the elastic membrane through the open rotating plates of each mount, causing the elastic membrane to vibrate, and the vibration of the elastic membrane causes the pressure in the fluid chamber to become extremely high. As a result, vibrations in the muffled sound range of the power unit can be effectively reduced. In other words, the vibration damping effect described above makes it possible to reliably reduce vibrations in a wide range of frequencies from the first roll movement of the power unit to the muffled sound range.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the overall configuration of an embodiment of the present invention, in which 1 is an automobile body as a base, and 2 is, for example, a horizontal engine as a power unit mounted and supported at the bottom of the engine compartment of the vehicle body 1. Support brackets 3.3 extending substantially horizontally are integrally provided on both the front and rear sides of the engine 2 across the crankshaft 2a as a roll axis, and between each bracket 3 and the vehicle body 1, In other words, the engine 2 is placed 11 on both sides of the crankshaft 2a of the engine 2.
Mounts 4, 4 for elastically supporting the body 1 are arranged.

Each of the mounts 4 includes a cylindrical case 5 that is fixed to the vehicle body 1 and has open upper and lower surfaces, seals the upper opening of the case 5 in a liquid-tight manner, and is connected to each support bracket 3 of the engine 2. The lower opening of the case 5 is made liquid-tight by an elastic membrane 8 (diaphragm) made of rubber or the like that is thinner than the elastic wall 7. A sealed liquid chamber 9 is created in the case 5 by the bullet 1 raw wall 7 and the elastic membrane 8.
is formed, and a liquid as an incompressible fluid is sealed in this liquid chamber 9. Therefore, the elasticity 18 is the liquid chamber 9
It forms part of the wall of the liquid chamber 9, and is provided so as to expand and contract according to pressure changes within the liquid chamber 9.

Further, an opening 5a is formed in the side shell of the case 5 of both the mounts 4, 4, and each end of a communicating tube 10 is integrally connected to the opening 5a. ,
The liquid chambers 9.9 of both mounts 4, 4 are communicated with each other to allow movement of liquid, and pressure changes in both liquid chambers 9, 9 are correlated with each other.

Furthermore, as shown in enlarged detail in FIG. A flange-shaped first stopper member 11 protruding into the liquid chamber 9 from above is integrally formed, and a ring-shaped second stopper member 12 is provided between the first stopper member 11 and the elastic membrane 8. is aligned with the first stopper member 11 at a constant interval, and between the two stopper members 11 and 12, a first movable plate 13 made of a circular plate-shaped hard rubber or the like connects the liquid chamber 9 to the communication pipe 10. The first movable plate 13 and A ring groove 12a is formed on the inner peripheral surface of the second stopper member 12 disposed between the elastic member 11!8.
is formed in the ring groove 128, and a disk-shaped second movable plate 14 made of hard rubber or the like is formed so as to partition the liquid chamber 9 closer to the elastic membrane 8 than the first movable plate 13. It is movably arranged within 12a with a predetermined movable clearance δ2.

Further, the ring-shaped second stopper portion vJ12 has orifices 15, 15 . ... is formed through it. That is, this orifice 15.15. ... are arranged so as to bypass the second movable plate 14.

The movable clearance δ1 of the first movable plate 13 is smaller than the amplitude during roll vibration of about 5H2 due to acceleration/deceleration operation of the engine 2, etc. Each is set to a value larger than the amplitude during engine shake of about 10 to 15 Hz.

On the other hand, the movable clearance δ2 of the second movable plate 14 is set to a value that is larger than the amplitude at the time of engine shaking and larger than the amplitude of vibration of 80 to 100 Hz at the peak of engine noise that causes muffled noise. ing. Therefore, the movable clearance δ1 of the first movable plate 13 is set to be larger than the movable clearance δ2 of the second movable plate 14.

Therefore, in this embodiment, when the engine 2 rolls vibrates around the crankshaft 2a at about 5 Hz due to its acceleration/deceleration, etc., the first and second Movable plate 13
．． Each of the 14 movable clearances δ1. Since both δ2 are set small, the movable clearance δ1,6
Due to the amplitude of 2 or more, both rotating plates 13.14 are stopped by being restricted by the ring grooves 128 of both stopper members 11.12 and the second stopper member 12, respectively, and the stopped first movable plate 13 closes the liquid chamber 9. is the communication part with the communication pipe 10 (
The opening 5a) of the case 5 and the elastic membrane 8 are in a closed state. For this reason, the liquid in the liquid chamber 9 stops flowing toward the elastic membrane 8 side, and moves to the liquid chamber 9 of the other mount 4 through the communication pipe 10, and due to the unidirectional phenomenon of the liquid passing through the communication pipe 10. The damping effect reduces roll vibration of the engine 2, and its transmission rate to the vehicle body 1 is suppressed.

In addition, during the so-called engine shake in which the engine 2 vibrates vertically at a frequency of about 10 to 15 Hz due to additional force from the road surface on which the automobile is running or unbalance of the wheels, the above-mentioned first Since the movable clearance δ1 of the movable plate 13 is set to be large and the movable clearance δ2 of the second movable plate 14 to be small, the first movable plate 13 can move without being restricted by both stopper members 11 and 12. However, the second movable plate 14 is restricted in movement by the ring groove 12a of the second stopper member 12 and stops.
The liquid chamber 9 is closed midway. Also, since the engine shake is captured in the vertical direction, both mounts l-4 are
, 4 do not exchange liquid with each other through the communication pipe 10.

As a result, as the liquid chamber 9 is closed by the second movable plate 14, the liquid in the liquid chamber 9 flows through the orifices 15, 15. The engine shake is reduced by the damping effect due to the synergistic phenomenon of liquid flowing into and out of the elastic membrane 8 side portion through the orifices 15, 15, and so on.

Furthermore, engine 2 makes a muffled sound at 80 to 100Hz.
When one movement is made at the above frequency, each movable clearance δ1. Since both δ2 are set large, the two rotating plates 13.14 move without being restricted by the ring grooves 12a of the two stopper members 11.12 and the second stopper member 12, respectively. The situation in the liquid chamber 9 is the same as if both rotating plates 13 and 14 were not present. For this reason, the elastic membrane 8 expands and contracts in response to the vibrations of the engine 2, and this deformation of the elastic membrane 8 suppresses the pressure rise in the liquid chamber 9, reducing the rigidity of each mount 4, and as a result, engine noise The transmission rate of change to the vehicle body 1 is reduced.

Therefore, by using one type of mounts 4, 4, it is possible to reliably and effectively reduce the transmission rate of vibrations from the roll vibration of the engine 2 to the muffled sound range to the vehicle body 1.

In the above embodiment, the mounting device elastically supports the engine 2 on the vehicle body 1. However, in order to reduce vibrations, noise, etc., the present invention uses an elastic support plate for a power unit other than the engine as a base. Needless to say, the present invention can also be applied to a mounting device designed to be used as a mounting device.

(Effects of the Invention) As described above, according to the present invention, there is provided a fluid chamber disposed on both sides of the roll shaft of a power unit such as an engine, and in which an incompressible fluid is sealed. A part of the wall of the fluid chamber is formed of an elastic membrane that deforms in response to changes in fluid chamber pressure, and the mount elastically supports the power unit on a base such as the vehicle body, and the fluid chambers of each mount are connected to each other to allow fluid flow. A first movable plate located on the side away from the elastic membrane and a first movable plate located on the side remote from the elastic membrane, and a first movable plate located on the side remote from the elastic membrane, and two movable plates, the second movable plate being positioned, and an orifice arranged to bypass the second movable plate, the movable clearance of the first movable plate being larger than the movable clearance of the second movable plate; Due to the jerky motion, when the power unit performs a large-amplitude roll motion, both rotating plates are closed to allow the fluid in the communication tube to resonate, and during medium-amplitude vibrations such as shaking, only the first movable plate is closed and the orifice is closed. Furthermore, when imaging small wall widths in the muffled sound range, both rotary plates are opened and the elastic membrane is moved, reducing the amount of imaging required. It is possible to reliably reduce a wide range of imaging from the low frequency range to the muffled sound range, and to greatly improve the sound insulation and vibration damping properties of the mounting device with a simple structure.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially cutaway front view showing the overall configuration of a mounting device, and FIG. 2 is an enlarged sectional view of the mount. DESCRIPTION OF SYMBOLS 1... Vehicle body, 2... Engine, 2a... Crankshaft, 4... Mount, 8... Elastic membrane, 9... Liquid chamber, 10... Communication pipe, 13... First movable plate, 14.
... Second movable plate, 15... Orifice, δ1. δ2・
・Movable clearance.

Claims (1)

[Claims] (1) It has a fluid chamber that is placed on both sides of the roll shaft of a power unit such as an engine, and has an incompressible fluid sealed inside, and a part of the wall of the fluid chamber responds to changes in fluid chamber pressure. A mount that is formed of an elastic membrane that deforms accordingly and elastically supports the power unit on a base such as a vehicle body, and the fluid chambers of each mount communicate with each other to allow fluid movement and correlate pressure changes in both fluid chambers. a first movable plate arranged to partition the fluid chamber on the side closer to the elastic membrane than the communication portion with the communication tube; A movable second movable plate disposed so as to be partitioned from the first movable plate on the side closer to the elastic membrane, and an orifice disposed so as to bypass the second movable plate; A power unit mounting device characterized in that a movable clearance is set larger than a movable clearance of a second movable plate.